人教版（2023）选择性必修第二册Unit 1Science and Scientists Discover useful structures 课件(共25张PPT)

第第页人教版（2023）选择性必修第二册Unit1ScienceandScientistsDiscoverusefulstructures课件(共25张PPT)(共25张PPT)

Discoveringusefulstructures

UNIT1ART

动词不定式作主语和表语

Theymustlearntorecognisebadhabitsearlyandmakeappropriatechanges.

Wemakeachoicetodosomething,andthenwerepeatitoverandoveragain.

Therewardmakesusmuchmorelikelytocontinuethehabitcycle.

Tofacilitateapositivechangeinourbadhabits,wemustfirstexamineourbadhabitcyclesandthentrytoadaptthem.

Forexample,whenwecometoanescalator(cue),ournormalroutineistorideit.

Toreachthegoalofchange,apersonmustshowsomedisciplineandrepeatedlytakemanysmallsteps.

object宾语

attribute定语

complement补足语

adverbial状语

object宾语

predicative表语

adverbial状语

Tip1:

动词不定式可以在句中作______、______、______、______、______、________的成分。

主语

宾语

表语

定语

状语

补足语

Readthesesentencesandfillintheblanksusingthecorrectwords.

Perhapsthebest_____tounderstandWesternartistolookatthedevelopmentofWesternpaintingoverthecenturies.

DuringtheMiddleAges,the_______ofWesternartwastoteachpeopleaboutChristianity.

Inthiswork,Monet’s____wastoconveythelightandmovementinthescene...

___________________________wasnolongershowreality,butinsteadtoaskthequestion,“Whatisart”

way

purpose

aim

Whattheyattemptedtodo

动词不定式在句中作表语

1.结构

动词不定式可以放在be和become,sound,taste等__________后

面作表语，由“(to)+动词原形”构成。

2.时态

动词不定式作表语时，如果不定式和逻辑主语之间是主动关系应使用__________如果是被动关系应该使用___________。

例1：Hisgoalis_____________(be)avolunteeratthelocalhospitalinthecomingholidays.

例2：Hisgoalis______________(admit)intoPekingUniversitythissummer.

:

动词不定式

系动词

tobecome

tobeadmitted

todo

tobedone

Summarizing

“不定式作表语”的实质是：be是系动词，be前的主语和be后的表语是同位概念，不定式作表语对主语的内容做具体说明作用，主语往往是表示“目的，目标，想法，愿望，任务，责任等”的名词，如：____________________________________________________________________________________________________________还可以由what或者all引导的名词性从句等。

intention,plan,purpose,aim,duty，hope，idea，concern，job，plan，problem，suggestion，wish,chance,method

Lead-in

1.Nottograspfirmlyisnottograspatall.

2.Whathewantedtosuggestwastocutdownthepriceandincreasethesales.

3.Heistocleantheroom.

4.Heseems(tobe)depressed.

5.Theplanproves(tobe)successful.

【自主发现】上面句中动词不定式形式，通常放在______________之后，在句中作_________。

连系动词

表语

Tip1：动词不定式作表语时，说明主语的具体内容或目的，主语一般是：_________________________________________________

___________________或者以________________________。

Tip2:wh-词+动词不定式句式：根据表达需要，在作表语的不定式前，还可添加疑问代词或疑问副词，包括what,who,how,when,where等。

eg:Whattheywantedtoknowwaswhentoholdanartexhibitionintheircity.

what引导的名词性从句

aim,purpose,dream,decision,task,difficulty,suggestion,

hope,duty,way等

常见动词不定式作表语情况：

1.Mysuggestionistocarryouttheplanimmediately.

2.WhatIwouldsuggestisnottoputoffthemeeting.

3.Watermustbepureifitistobedrunk.

4.Allofhispersonalstuffsarenottobesold.

1.Allhewantedwas_______________.

他只想一个人待着。

2.TheleastIcandotohelpis________________.

我所能帮的最起码的事是借给她一辆车。

tobeleftalone

tolendheracar

Tip3：当主语包含定语从句且其先行词为代词_____或者主语被___________________或形容词________修饰时，其后可接“系动词+不定式”作句子的表语。

only,first,one,least

最高级

all

1.Whois_____________thefire

谁应为这场大火承担责任？

2.Thehouseis_________.此房出租。

Tip4：某些动词不定式(短语)作表语时，需用主动形式表示__________。

toblamefor

tolet

被动意义

Tip5:动词不定式可与疑问词when、where、how、what、which、who等组合，构成___________，在句中可作______、______和______。

不定式短语

Observeandexplore.

Whentostarthasnotbeendecidedyet.

DoyouknowwheretofindTom

Mymainconcernishowtogetthereontime.

subject主语

object宾语

predicative表语

主语

宾语

表语

注意：

动词不定式(短语)作表语时，一般情况下不定式符号to不能省略，但当主句主语部分含有实义动词do的某种形式时，可省略作表语的动词不定式（短语）里的不定式符号to:

1.我们试图要做的是挽救地球。

Whatwe’retryingtodoissaveEarth.

________________________________________________________________________________

2.晚上他做过的唯一的事是读报纸。

Intheeveningtheonlythinghedidwasreadthenewspaper.

________________________________________________________________________________

1.动词不定式作主语，表示具体的、一次性的或者表示将来含义的动作，且谓语动词常用_______。如：

Tobecalmindangerisveryimportant/significant.

Towinthegameispossible.

Toseeistobelieve.

Toworkwithhimisagreatpleasure

2.动词不定式短语作主语时，为了保持句子平衡，往往用__作形式主语，而将动词不定式短语置于句末。如：

ItisimportanttolearnEnglishwell.

单数

Presentation

it

It做形式主语，其常见句型如下：

1.It＋is＋名词＋todosth

It’sourdutytoprotectthenaturalenvironment.

2.Ittooksbsometime/money＋todosth

Ittookusthreehourstofinishthereport.

3.It＋be＋形容词＋for/ofsb＋todosth

It’sverygenerousofyoutodonateusalargesumofmoney.

Itisnecessaryforchildrentoformgoodhabitsatanearlyage.

4.Itseems/appears＋形容词＋todosth

Itseemedimpossibletocatchupwiththemin20minutes.

补充：动词不定式作表语和v-ing作表语的区别

动词不定式和v-ing作表语时，要注意与句子的主语在形式上保持一致，即若句子的主语为v-ing，则表语也应使用v-ing；若主语为动词不定式，则表语也应使用动词不定式。

Toseeistobelieve.=Seeingisbelieving.

动词不定式和v-ing作表语时可换用，但以下情况除外:

当动词所表达的是某一特定的行为，尤其是将来的行为或有待于实现的行为时，通常用动词不定式作表语。

Herbestwishistoputhernewideasintopractice.

若动词所表达的并不强调动作，而是表示主语的内容，则通常用v-ing作表语。

Myfavoritesportisswimming.

WhatIhatemostisbeinglaughedat.

Usethecorrectformsofthewordstofillintheblanks.

________(read)aloudisgoodforyourEnglishlearning.

Itisquitenecessary________(read)itagain.

________(see)istobelieve.

________(see)isbelieving.

拓展:todoasthesubjectVSdoingasthesubject

Reading

toread

Tosee

Seeing

Tip6:动词不定式和动名词作主语的区别：

_______作主语特指一次性的、具体的动作；_______作主语泛指一般的或习惯性的动作。且作主语和表语的不定式或动名词需保持________。

todo

doing

一致

动词不定式（短语）作表语省略to的情况

动词不定式(短语)作表语时，一般不定式符to不能省略,但以下情况下可省略：

1.all作主语其后的定语从句有do的某种形式时：

Allweneedtodoisliveeachdaywithhope.

2.what引导的从句作主语时，从句中含有do的某种形式时：

WhatIwanttodoistakeaholidayrightaway.

3.主语被only，first，one，least或形容词最高级修饰，其后的定语从句或短语中有do的某种形式时：

Intheeveningtheonlythinghedidwasreadthenewspaper.

Ⅰ.单句语法填空

Themostmeaningfulthinghewantstodois______(help)thepoor.

Thisyear,hisplanis_______(make)somechangesintheteachingmethod.

WhatIsuggestis_______(start)workatonce.

Oneofherhobbiesis_________(collect)stamps.

Ithinkitisyourbrotherwhois_______(blame)fortheaccident.

即学即练

help

tomake

tostart

collecting

toblame

Supposeyouare________(be)ajournalistforChinaDaily,doyouknowwhatkindofjobstheyhave

Youare______________(reward)ifyouhavemadeabreakthrough.

Thestudentstrustherverymuch;asaresult,heradviceis__________(influence)theirdecisions.

tobe

toberewarded

toinfluence

3.Medicalexpertssaythemosteffectivewaytopreventthespreadofdiseaseisforpeople________(wash)theirhandswithsoapandwater.

4.Thenextstepis________surethatyouknowexactlywhatisrequired.

5.Thepurposeofeducationis__________(develop)afinepersonalityinchildren.

towash

tomake

todevelop

1.Themottoofthelittleboywhowassufferingfromamusclediseasewas_______(live)onedayatatime.

2.Itisyou,includingyourcousin,that____________(blame)forthelossofthegoldenchance.

tolive

aretoblame

Practise

Matchthesentencehalves.

Discoverwhatthesesubjectsshareincommonbyusingthefollowingtable.

Meaning/ConstructSubject

anactionforsomepurpose

awayofaction

advice

responsibility

aclause

intention,plan,purpose,aim

way,things,business,habit,principle,vocation,chance,method

suggestion,thought

duty,order

What...attempted...,All...wanted...

Theyoungsinger'sintentionofperformingthesongwas___________________________________.(与歌迷们分享他对摇滚乐的热爱)

Thebestwaytodobusinessis____________________

___